Answer:
(1 + sin x)(1 – sin x) = cos^2x
1 - sin^2x = cos^2x
cos^2x = cos^2x
Step-by-step explanation:
Simplify the left hand side:
(1 + sin x)(1 – sin x) = cos^2x
1 - sin^2x = cos^2x
Using the Pythagorean Identity, we can see that the two sides are equivalent if you subtract sin^2x from both sides:
sin^2x + cos^2x = 1
cos^2x = 1 - sin^2x
Lastly, write it out:
(1 + sin x)(1 – sin x) = cos^2x
1 - sin^2x = cos^2x
cos^2x = cos^2x
